Rules of Noon Sakin and Tanween – نون ساكن وتنوين
- Izhar (making clear) – إظهار
- Idgham (merging) – إدغام
- Iqlab (changing) – اقلاب
- Ikhfa (hiding) – اخفاء
In this case the Noon is read clearly. There are six letters which when immediately follow the Noon sakin or Tanween, they cause them to be pronounced clearly. These letters are the Throat letters, (Halqi) or the six letters which are articulated from the throat:
Example Noon Sakin;
منهم، من أخيه ، انعمت، من خوف، من غاب ، لمن خشي
Example Noon Tanween;
أجر غير، عليماً حكيما، محمداً عبده، نار حامية
In this case the Noon is merged into the next letter either partially or completely. There are two subdivisions of the Idgham:
Idgham with a Ghunnah (nasalization);
They are the letters that make up the word (ي ن م و) when a reader is reciting the Quran and there is a Noon sakin or Tanween at the end of a word, and the first letter of the next word is one of these four letters, the Idgham with a Ghunnah rule is then applied. This means that the Noon is not pronounced clearly, instead it is inserted, or merged into the next letter, with the Ghunnah, or nasalization, that is part of the Noon.
مَنْ يَّقول، منْ نَّبي، منْ مَّآء، منْ وَّال
Idgham without any Ghunnah;
The two remaining letters of the group(s) are the letters that comprise this rule. They are the (ل،ر) when one of these two letters begins the word that follows one that has a Noon sakin or Tanween at the end of it, we then completely merge the Noon into the next letter, which is either Laam or Raa with no Ghunnah. Therefore, this division of the Idgham is also called complete insertion without any Ghunnah.
منْ رَّبِّهم،منْ لَّدُنْك
IQLAB (The Changing): إقلاب
The changing of noon saakin or the tanween into a Meem, when followed by a Baa, with the observance of the ghunnah, and hiding of the Meem.
منْ بعد،عليمٌ بذات الصدور
IKHFA (hiding or concealment): إخفاء
The pronunciation of a non-voweled letter stripped of any shaddah, characterized somewhere between an IZHAR and an IDGHAM with a ghunnah remaining on the first letter, in this case the Noon saakinah and the tanween. The letters of the IKHFA for the Noon saakinah and tanween are all the remaining letters in the Arabic alphabet after we remove the letters thatcause IZHAR, IDGHAM and IQLAB, there are 15 letters in the Arabic alphabet.